Beyond the familiar sweet, sour, salty, and bitter sensations, another taste subtly enhances many foods. This distinctive taste often goes unrecognized, yet it plays a fundamental role in our culinary experiences.
What is Glutamate Taste?
Glutamate taste, scientifically known as umami, is the fifth basic taste. The term “umami” translates from Japanese as “pleasant savory taste,” describing a brothy or meaty sensation. Japanese scientist Kikunae Ikeda first identified this taste in 1908, isolating glutamic acid from kombu seaweed. Umami is a fundamental taste, similar to sweet, sour, salty, and bitter, because it possesses its own dedicated receptors on the tongue. The sensation is characterized by a pleasant, savory, and full-bodied taste that spreads across the tongue, leaving a lasting aftertaste and inducing a mouth-watering effect.
How We Detect Glutamate
Our ability to detect glutamate begins with specialized structures on our tongue called taste buds. Each taste bud contains various taste receptor cells designed to interact with specific molecules. When glutamate molecules bind to these receptors, a signal is sent to the brain, where it is interpreted as the umami taste. The perception of umami can be significantly enhanced by the synergistic effect of certain nucleotides, such as inosine monophosphate (IMP) and guanosine monophosphate (GMP). These nucleotides, found in many foods, can amplify the umami sensation from glutamate by up to fifteen-fold, making the taste more intense and prolonged.
Foods Rich in Glutamate
Glutamate is an amino acid found naturally in many foods and is also produced by the human body. Common natural sources of free glutamate include aged cheeses, ripe tomatoes, mushrooms, cured meats, soy sauce, and seaweed. Fermented foods, broths, and certain seafood also contribute to dietary glutamate intake. Cooking methods such as simmering, roasting, grilling, aging, and fermentation can increase the levels of free glutamate in foods by breaking down proteins, enhancing the savory taste. Monosodium glutamate (MSG) is a purified form of glutamate that provides the same umami taste as naturally occurring glutamate, and it is often used as a flavor enhancer in various dishes, including soups, stews, and snack foods.
Health and Dietary Considerations
Glutamate is a naturally occurring amino acid present in virtually all protein-containing foods and is the most abundant amino acid in the human body. It plays a role in various bodily functions, including metabolism and brain activity.
The human body does not differentiate between glutamate naturally present in food and glutamate added as MSG. Major health organizations worldwide, including the U.S. Food and Drug Administration (FDA) and the World Health Organization (WHO), classify MSG as safe for consumption.
While “MSG symptom complex” has been reported, scientific studies have largely failed to establish a consistent, causal link between MSG consumption and these reported symptoms in the general population. Any reported sensitivities are typically mild and transient, often occurring only with large doses (3 grams or more) consumed on an empty stomach.
Glutamate, both natural and added, can enhance flavor, potentially allowing for reduced salt content in dishes while maintaining palatability. It may also improve food intake in certain populations, such as elderly individuals with reduced appetite, by making meals more appealing.